Method for testing resonant capacitor of chip

Abstract

The invention discloses a method for testing a chip resonant capacitor. The method comprises the following steps: acquiring a resistance value of a test resistor in an RC circuit and a first time when the test capacitor is charged to a preset voltage when a capacitance value of the test capacitor is at different preset values; after the preset capacitor is connected to the output end of the RC circuit, obtaining the resistance value of the test resistor and the second time when the preset capacitor is charged to the preset voltage when the capacitance value of the test capacitor is different from the preset values; determining a matched resistance value of the test resistor and a matched capacitance value of the test capacitor according to the actual capacitance value of the preset capacitor, the first time and the second time; and after the test resistor and the test capacitor of the RC circuit are matched according to the matching resistance value and the matching capacitance value, the resonant capacitance of the to-be-tested chip is tested based on the matched RC circuit. The test of the chip resonant capacitance is realized, the test accuracy is improved, and the test cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit testing, and in particular to a method for testing a chip resonant capacitor. Background Art

[0002] Due to its non-contact and convenient features, RFID chips have been widely used in the fields of second-generation ID cards, bus cards, access cards, etc. The size of the load directly affects the performance of the chip. Therefore, the test of small load capacitance and the test cost are becoming more and more important with the widespread application of RFID.

[0003] In existing testing technology, mid-to-high-end specific testers with capacitance testing functions are usually used for testing. However, such testers can generally only measure relatively large capacitances, and the equivalent capacitance of the chip can only be guaranteed by design and cannot be quantified by testing, thereby failing to guarantee the performance of the chip. Summary of the invention

[0004] The present invention provides a chip resonant capacitor testing method to solve the problem of great difficulty and low precision in testing the chip resonant capacitor.

[0005] According to one aspect of the present invention, a method for testing a chip resonant capacitor is provided, which is performed using a resonant capacitor testing device, the testing device comprising a testing machine and an RC circuit, the testing machine being connected to the RC circuit; the method comprising:

[0006] Obtaining a first time when the test capacitor is charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor in the RC circuit are at different preset values;

[0007] After the output end of the RC circuit is connected to a preset capacitor, obtaining a second time for the preset capacitor to be charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor are at different preset values;

[0008] Determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to an actual capacitance value of the preset capacitor, the first time, and the second time;

[0009] After matching the test resistance and the test capacitance of the RC circuit according to the matching resistance value and the matching capacitance value, the resonant capacitance of the chip to be tested is tested based on the matched RC circuit.

[0010] Optionally, determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to the capacitance value of the preset capacitor, the first time, and the second time includes:

[0011] Determining, according to the difference between the second time and the first time, a calculated capacitance value of the preset capacitance when the test resistor and the test capacitor are at different preset values;

[0012] The matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the actual capacitance value of the preset capacitance and the calculated capacitance value of the preset capacitance; the actual capacitance value of the preset capacitance is of the same order of magnitude as the capacitance value of the resonant capacitance of the chip to be tested.

[0013] Optionally, determining, according to the difference between the second time and the first time, a calculated capacitance value of the preset capacitance when the test resistor and the test capacitor are at different preset values ​​includes:

[0014] T2-T1=(R0+R1)(C0+C1)-(R0+R1)C0;

[0015] C1=(T2-T1) / (R0+R1);

[0016] Among them, T2 is the second time, T1 is the first time, R0 is the equivalent impedance of the test machine, R1 is the preset value of the test resistor, C0 is the preset value of the test capacitor, and C1 is the calculated capacitance value of the preset capacitor.

[0017] Optionally, determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to an actual capacitance value of the preset capacitor and a calculated capacitance value of the preset capacitor includes:

[0018] Subtracting the actual capacitance value of the preset capacitor from the calculated capacitance values ​​of the plurality of preset capacitors respectively to determine the absolute values ​​of the plurality of differences;

[0019] Selecting a calculated capacitance value of a preset capacitance corresponding to a minimum value among the absolute values ​​of the plurality of differences as a preset capacitance value of the preset capacitance;

[0020] The preset value of the test resistor corresponding to the preset capacitance value is used as the matching resistance value of the test resistor, and the preset value of the test capacitor is used as the matching capacitance value of the test capacitor.

[0021] Optionally, the actual capacitance value of the preset capacitor is of the same order of magnitude as the calculated capacitance value of the preset capacitor.

[0022] Optionally, the capacitance value of the test capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested.

[0023] Optionally, the test machine includes a comparator and a driver; a first input end of the comparator is connected to an output end of the RC circuit, a second input end of the comparator is used to input the preset voltage, an input end of the driver is connected to an output end of the comparator, and an output end of the driver is connected to an input end of the RC circuit; obtaining the first time or the second time includes:

[0024] When the driver drives the RC circuit to charge, a pulse signal is synchronously output, and the pulse signal is counted;

[0025] When the output signal of the comparator jumps, the first time or the second time is determined according to the number of the pulse signal.

[0026] Optionally, a driving chip is further included, and the test machine is connected to the RC circuit via the driving chip; the driver drives the RC circuit to charge, including:

[0027] The driving chip drives the RC circuit to charge according to the driving signal output by the driver.

[0028] Optionally, before testing the resonant capacitance of the chip to be tested based on the matched RC circuit, the method further includes:

[0029] Adjust the chip mode to test mode.

[0030] Optionally, after testing the resonant capacitor of the chip to be tested, the method further includes:

[0031] According to the obtained capacitance value of the chip to be tested, it is determined whether the capacitance value of the chip to be tested is within a preset value of the chip resonant capacitance.

[0032] The technical solution of the embodiment of the present invention is to obtain the first time when the test capacitor is charged to the preset voltage by obtaining the resistance value of the test resistor and the capacitance value of the test capacitor in the RC circuit at different preset values. The preset capacitor is connected to the output end of the RC circuit, and the resistance value of the test resistor and the capacitance value of the test capacitor are obtained at different preset values. The second time when the preset capacitor is charged to the preset voltage; the matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the actual capacitance value of the preset capacitor, the first time and the second time. When the test resistor is the matching resistance value and the test capacitor is the matching capacitance value, the difference between the actual capacitance value of the preset capacitor and the calculated capacitance value is the smallest, that is, when the test resistor is the matching resistance value and the test capacitor is the matching capacitance value, the test accuracy of the preset capacitance can be improved. After matching the test resistor and the test capacitor of the RC circuit according to the matching resistance value and the matching capacitance value, the resonant capacitance of the chip to be tested is tested based on the matched RC circuit, thereby improving the resonant capacitance test accuracy of the chip to be tested corresponding to the capacitance value of the preset capacitor. The technical solution of the embodiment of the present invention realizes the test of chip resonant capacitance, improves the accuracy of test results, has a simple test method, low test cost, and can be adjusted and optimized according to different test requirements, with good flexibility.

[0033] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 is a flow chart of a chip resonant capacitor testing method provided according to an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of a chip resonant capacitor testing method provided according to an embodiment of the present invention;

[0037] Figure 3 is a flow chart of a method for determining a resistance to be measured and a capacitance to be measured by an RC circuit provided in an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of a method for determining a resistance to be measured and a capacitance to be measured by an RC circuit according to an embodiment of the present invention;

[0039] Figure 5 It is a circuit connection diagram of an RC circuit embedded chip provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] Figure 1 A flow chart of a method for testing a chip resonant capacitor is provided for an embodiment of the present invention. This embodiment is applicable to the testing of a chip resonant capacitor and is performed using a resonant capacitor testing device. Figure 2 A schematic diagram of the structure of a chip resonant capacitor testing device provided by an embodiment of the present invention. Figure 2 As shown, the test device includes a test machine and an RC circuit, and the test machine is connected to the RC circuit. Among them, the RC circuit 201 includes a test resistor R1 and a test capacitor C0, the first end of the test resistor R1 is connected to the output end of the test machine, and the second end of the test resistor R1 is connected to the first end of the test capacitor C0, and serves as a test interface of the test device. At the same time, the first end of the test capacitor C0 is connected to the input end of the test machine, so that the test machine can obtain the potential of the first end of the test capacitor C0. The second end of the test capacitor C0 is grounded. During the test process, the test interface of the test device is connected to the first test end of the chip to be tested 202, and the second test end of the chip to be tested 202 is grounded, which is used to implement the test of the resonant capacitor Cx of the chip to be tested. As shown Figure 1 As shown, the method includes:

[0043] S101, obtaining the first time when the test capacitor is charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor in the RC circuit are different preset values.

[0044] Among them, the RC circuit includes a test resistor and a test capacitor, and the RC circuit may include multiple groups of different test resistors and test capacitors for selecting the matching resistance value of the test resistor and the matching capacitance value of the test capacitor. The first time is the time required for the test capacitor in the RC circuit to charge to a preset voltage. During the test process, the output end of the tester can send a charging voltage to charge the test capacitor. At the same time, the input end of the tester can test the potential of the first end of the test capacitor, and when the potential of the first end of the test capacitor reaches the preset voltage, the tester can determine the first time. An exemplary preset voltage can be 63.2% of the charging voltage. The final voltage value can be determined according to the capacitance of the test capacitor. In the RC circuit, different test resistors and / or test capacitors correspond to different first times. Exemplarily, the resonant capacitance of the chip to be tested is at the pF level, and the preset resistance to be tested can be respectively 1KΩ / 1.5KΩ / 2KΩ / 4.7KΩ and the preset capacitance to be tested can be respectively 10pF / 15pF / 20pF / 33pF respectively connected to the circuit in sequence, and the first time when the test capacitor is charged to the preset voltage when testing different preset values.

[0045] S102, after the output end of the RC circuit is connected to a preset capacitor, obtaining a second time for the preset capacitor to be charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor are different preset values.

[0046] Among them, the preset capacitor can be a capacitor with a fixed capacitance. After the preset capacitor is connected, the first end of the preset capacitor is connected to the first end of the test capacitor, and the second end of the preset capacitor is grounded. At this time, the preset capacitor and the test capacitor are connected in parallel. During the test process, the charging voltage can also be sent through the output end of the test machine to charge the test capacitor and the preset capacitor. At the same time, the input end of the test machine can test the potential of the first end of the test capacitor. When the potential of the first end of the test capacitor reaches the preset voltage, the test machine can determine the second time. At this time, the second time is the time required for the test capacitor and the preset capacitor to be charged to the preset voltage at the same time. Similarly, different preset values ​​of the test capacitor and the test resistor correspond to different second times. Exemplarily, the resonant capacitor of the chip to be tested is at the pF level, and the preset capacitor connected to the output end of the RC circuit is also at the pF level. Then, the preset resistance to be tested is 1KΩ / 1.5KΩ / 2KΩ / 4.7KΩ and the preset capacitance to be tested is 10pF / 15pF / 20pF / 33pF respectively. Connected to the circuit in turn, the preset capacitor is charged to the second time of the preset voltage when testing different preset values.

[0047] S103, determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to an actual capacitance value of the preset capacitor, the first time, and the second time.

[0048] Among them, the charging time is equal to the product of the charging resistance and the charging capacitance. The charging resistance corresponding to the first time is the sum of the equivalent resistance of the test machine and the test resistance, and the charging capacitance corresponding to the first time is the test capacitance. The charging resistance corresponding to the second time is the sum of the equivalent resistance of the test machine and the test resistance, and the charging capacitance corresponding to the second time is the sum of the test capacitance and the preset capacitance. At this time, the difference between the first time and the second time is the charging time of the preset capacitance, so that the calculated capacitance value of the preset capacitance when the test resistance and the test capacitance are different preset values ​​can be determined according to the second time and the first time, and then the matching resistance value of the test resistance and the matching capacitance value of the test capacitance can be determined according to the minimum difference between the actual capacitance value of the preset capacitance and the calculated capacitance value under different conditions of the preset capacitance. Thus, when the test resistance is the matching resistance value and the test capacitance is the matching capacitance value, the difference between the actual capacitance value of the preset capacitance and the calculated capacitance value is the smallest, that is, when the test resistance is the matching resistance value and the test capacitance is the matching capacitance value, the test accuracy of the preset capacitance can be improved, that is, when the test resistance is the matching resistance value and the test capacitance is the matching capacitance value, the capacitance test accuracy of the order of magnitude corresponding to the capacitance value of the preset capacitance can be improved. At the same time, the actual capacitance value of the preset capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested, thereby improving the test accuracy of the resonant capacitor of the chip to be tested when the capacitance value of the resonant capacitor of the chip to be tested is subsequently tested.

[0049] S104 , after matching the test resistance and the test capacitance of the RC circuit according to the matching resistance value and the matching capacitance value, testing the resonant capacitance of the chip to be tested based on the matched RC circuit.

[0050] Among them, the resistor to be tested in the RC circuit is connected to the matching resistance value of the test resistor, the test capacitor is connected to the matching capacitance value of the test capacitor, and the chip to be tested is connected to obtain the third time for the resonant capacitor of the chip to be tested to be charged to the preset voltage. The first end of the chip to be tested is connected to the first end of the test capacitor, and the second end of the chip to be tested is grounded. At this time, the chip to be tested and the test capacitor are connected in parallel. During the test process, the charging voltage can also be sent through the output end of the tester to charge the test capacitor and the resonant capacitor of the chip to be tested. At the same time, the input end of the tester can test the potential of the first end of the test capacitor. When the potential of the first end of the test capacitor reaches the preset voltage, the tester can determine the third time. At this time, the third time is the time required for the test capacitor and the resonant capacitor of the chip to be tested to be charged to the preset voltage at the same time. The resonant capacitor of the chip to be tested is determined according to the matching capacitance value of the capacitor to be tested and the third time.

[0051] The technical solution of the embodiment of the present invention is to obtain the first time when the test capacitor is charged to the preset voltage by obtaining the resistance value of the test resistor and the capacitance value of the test capacitor in the RC circuit at different preset values. The preset capacitor is connected to the output end of the RC circuit, and the resistance value of the test resistor and the capacitance value of the test capacitor are obtained at different preset values. The second time when the preset capacitor is charged to the preset voltage; the matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the actual capacitance value of the preset capacitor, the first time and the second time. When the test resistor is the matching resistance value and the test capacitor is the matching capacitance value, the difference between the actual capacitance value of the preset capacitor and the calculated capacitance value is the smallest, that is, when the test resistor is the matching resistance value and the test capacitor is the matching capacitance value, the test accuracy of the preset capacitance can be improved. After matching the test resistor and the test capacitor of the RC circuit according to the matching resistance value and the matching capacitance value, the resonant capacitance of the chip to be tested is tested based on the matched RC circuit, thereby improving the resonant capacitance test accuracy of the chip to be tested corresponding to the capacitance value of the preset capacitor. The technical solution of the embodiment of the present invention realizes the test of chip resonant capacitance, improves the accuracy of test results, has a simple test method, low test cost, and can be adjusted and optimized according to different test requirements, with good flexibility.

[0052] In some optional embodiments of the present invention, determining a matching resistance value of a test resistor and a matching capacitance value of a test capacitor according to a capacitance value of a preset capacitor, a first time, and a second time includes:

[0053] Determine, according to the difference between the second time and the first time, a calculated capacitance value of the preset capacitance when the test resistance and the test capacitance are at different preset values;

[0054] Among them, the charging resistance corresponding to the first time is the sum of the equivalent resistance of the test machine and the test resistance, and the charging capacitance corresponding to the first time is the test capacitance. The charging resistance corresponding to the second time is the sum of the equivalent resistance of the test machine and the test resistance, and the charging capacitance corresponding to the second time is the sum of the test capacitance and the preset capacitance. At this time, the difference between the first time and the second time is the charging time of the preset capacitance, so that the calculated capacitance value of the preset capacitance when the test resistance and the test capacitance are different preset values ​​can be determined according to the second time and the first time.

[0055] The matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the actual capacitance value of the preset capacitance and the calculated capacitance value of the preset capacitance; the actual capacitance value of the preset capacitance is of the same order of magnitude as the capacitance value of the resonant capacitance of the chip to be tested.

[0056] According to different resistances to be measured and capacitances to be measured in the RC circuit, multiple differences are determined according to the actual capacitance value of the preset capacitance and the calculated capacitance values ​​of the multiple preset capacitances. The matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the minimum difference between the actual capacitance value of the preset capacitance and the calculated capacitance value under different conditions of the preset capacitance.

[0057] In some optional embodiments of the present invention, determining the calculated capacitance value of the preset capacitance when the test resistor and the test capacitor are at different preset values ​​according to the difference between the second time and the first time includes:

[0058] T2-T1=(R0+R1)(C0+C1)-(R0+R1)C0;

[0059] C1=(T2-T1) / (R0+R1);

[0060] Among them, T2 is the second time, T1 is the first time, R0 is the equivalent impedance of the test machine, R1 is the preset value of the test resistance, C0 is the preset value of the test capacitance, and C1 is the calculated capacitance value of the preset capacitance.

[0061] Figure 3 The present invention provides a flowchart of a method for determining a resistance to be measured and a capacitance to be measured by an RC circuit. Figure 3 As shown, in some optional embodiments of the present invention, determining the matching resistance value of the test resistor and the matching capacitance value of the test capacitor according to the actual capacitance value of the preset capacitor and the calculated capacitance value of the preset capacitor includes:

[0062] S301 , subtracting the actual capacitance value of a preset capacitor from the calculated capacitance values ​​of a plurality of preset capacitors respectively to determine the absolute values ​​of a plurality of differences.

[0063] Among them, after the preset capacitor is connected to the output end of the RC circuit, the preset capacitor is connected in parallel with the capacitor to be tested in the RC circuit. The RC circuit may include multiple groups of different test resistors and test capacitors. The multiple groups of different test resistors and test capacitors are connected to the circuit to obtain the calculated capacitance values ​​of multiple preset capacitors. The absolute values ​​of the differences between the actual capacitance value of the preset capacitor and the calculated capacitance values ​​of the multiple preset capacitors are determined to determine the preset capacitance value of the preset capacitor.

[0064] S302 , selecting a calculated capacitance value of a preset capacitance corresponding to a minimum value among the absolute values ​​of a plurality of differences as a preset capacitance value of the preset capacitance.

[0065] Among them, the calculated capacitance value of the preset capacitance corresponding to the minimum value among the absolute values ​​of the multiple differences is the preset capacitance value of the preset capacitance, and the calculated capacitance value of the preset capacitance with the minimum absolute value of the difference is the matching value closest to the actual capacitance value. It can be ensured that a capacitance value closest to the actual measured value is found in a set of preset values, thereby achieving the best matching effect in the circuit.

[0066] S303: Using a preset value of the test resistor corresponding to the preset capacitance value as a matching resistance value of the test resistor, and using a preset value of the test capacitor as a matching capacitance value of the test capacitor.

[0067] Among them, the preset values ​​of the test resistor and the test capacitor corresponding to the preset capacitance value are used as the matching resistance value of the test resistor and the matching capacitance value of the test capacitor. This is because the purpose of the test capacitor is to simulate or test the performance of the circuit under actual working conditions, so using the same capacitance value as the design value can be tested more accurately. Use the test resistor and test capacitor matching values ​​in the actual circuit, and test to verify whether the performance of the circuit meets expectations.

[0068] In some optional embodiments of the present invention, the actual capacitance value of the preset capacitor is of the same order of magnitude as the calculated capacitance value of the preset capacitor.

[0069] Among them, the actual capacitance value of the preset capacitor and the calculated capacitance value of the preset capacitor are on the same order of magnitude to ensure that the circuit can work normally, so that when the test resistor is a matching resistance value and the test capacitor is a matching capacitance value, the difference between the actual capacitance value of the preset capacitor and the calculated capacitance value is minimized, and at the same time, the capacitance test accuracy of the order of magnitude corresponding to the capacitance value of the preset capacitor can be improved.

[0070] In some optional embodiments of the present invention, the capacitance value of the test capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested.

[0071] Among them, the capacitance value of the test capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested, so that when the test resistor is a matching resistance value and the test capacitor is a matching capacitance value, the test accuracy of the preset capacitance can be improved, and the capacitance test accuracy of the order of magnitude corresponding to the capacitance value of the preset capacitance can be improved. At the same time, the actual capacitance value of the preset capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested, so that when the capacitance value of the resonant capacitor of the chip to be tested is subsequently tested, the test accuracy of the resonant capacitor of the chip to be tested can be improved.

[0072] Figure 4 is a schematic diagram of a method for determining a resistance to be measured and a capacitance to be measured by an RC circuit according to an embodiment of the present invention. In some optional embodiments of the present invention, such as Figure 4As shown, the test machine 401 includes a comparator P1 and a driver D1; the first input terminal of the comparator P1 is connected to the output terminal of the RC circuit 402, the second input terminal of the comparator P1 is used to input a preset voltage, the input terminal of the driver D1 is connected to the output terminal of the comparator P1, and the output terminal of the driver D1 is connected to the input terminal of the RC circuit 402; obtaining the first time or the second time includes:

[0073] When the driver D1 drives the RC circuit 402 to charge, a pulse signal is synchronously output and the pulse signal is counted;

[0074] The driver D1 can send clock pulses, count the pulse signals through a counter, and determine the time by the number of pulse signals, so that the driver D1 can synchronously output pulse signals and count the pulse signals while driving the RC circuit 402 to charge, thereby accurately monitoring the charging process of the RC circuit 402.

[0075] When the output signal of the comparator P1 jumps, the first time or the second time is determined according to the number of pulse signals.

[0076] When the RC circuit 402 is charged to a preset voltage, the output signal of the comparator P1 will jump. It can be a rising edge (from low to high) or a falling edge (from high to low). When the output signal of the comparator P1 jumps, the pulse signal can be used to trigger a counter to count the jumps, and determine the first time or the second time according to the number of pulse signals.

[0077] Figure 5 A circuit board diagram of an RC circuit embedded in a chip is provided for an embodiment of the present invention. Figure 4 and Figure 5 In some optional embodiments of the present invention, a driving chip 501 is further included, and the test machine 401 is connected to the RC circuit 502 through the driving chip 501; the driver D1 drives the RC circuit 502 to charge, including:

[0078] The driving chip 501 drives the RC circuit 502 to charge according to the driving signal output by the driver D1 .

[0079] Wherein, the driver chip can receive control signals and control the switch states of other circuits according to these signals. The drive signal is an input signal received by the driver chip, which is used to indicate when the driver chip turns on or off its output. The drive signal can be a digital signal (such as high and low levels) or an analog signal (such as PWM pulse width modulation signal). When the output of the driver chip 501 is a high level, current can be provided to the RC circuit 502. The current flows to the capacitor through the resistor R1 and starts to charge the capacitor C0. Wherein, C1 is a preset capacitor, and R0 is the equivalent impedance of the test machine 401. After determining the matching resistance value of the test resistor and the matching capacitance value of the test capacitor, the preset capacitor C1 can be short-circuited and the chip to be tested is connected to the circuit.

[0080] In some optional embodiments of the present invention, before testing the resonant capacitance of the chip to be tested based on the matching RC circuit, the method further includes:

[0081] Adjust the chip mode to test mode.

[0082] The test mode allows the tester to access and control specific functions of the chip. Different chips may have different mechanisms to enter the test mode, such as through specific pin configurations, software commands, or special input signals. Send a specific test signal or command to the chip to turn on the test mode. After the test is completed, restore the chip from the test mode to the normal working mode as needed.

[0083] In some optional embodiments of the present invention, after testing the resonant capacitance of the chip to be tested, the method further includes:

[0084] According to the obtained capacitance value of the chip to be tested, it is determined whether the capacitance value of the chip to be tested is within a preset value of the chip resonant capacitance.

[0085] Among them, it is necessary to clarify the preset value of the chip resonant capacitor, which can be found in the chip data sheet or obtained through the specifications provided by the chip manufacturer. The obtained chip capacitance value to be tested is compared with the preset value of the chip resonant capacitor. If the measured value is within the tolerance range of the preset value, it is considered that the chip capacitance value to be tested meets the requirements.

[0086] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0087] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for testing a chip resonant capacitor, performed using a resonant capacitor testing device, the testing device comprising a testing machine and an RC circuit, the testing machine being connected to the RC circuit; characterized in that: The method comprises: Obtaining a first time when the test capacitor is charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor in the RC circuit are at different preset values; After the output end of the RC circuit is connected to a preset capacitor, obtaining a second time for the preset capacitor to be charged to a preset voltage when the resistance value of the test resistor and the capacitance value of the test capacitor are at different preset values; Determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to an actual capacitance value of the preset capacitor, the first time, and the second time; After matching the test resistance and the test capacitance of the RC circuit according to the matching resistance value and the matching capacitance value, the resonant capacitance of the chip to be tested is tested based on the matched RC circuit.

2. The method for testing chip resonant capacitor according to claim 1, characterized in that: Determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to the capacitance value of the preset capacitor, the first time, and the second time includes: Determining, according to the difference between the second time and the first time, a calculated capacitance value of the preset capacitance when the test resistor and the test capacitor are at different preset values; The matching resistance value of the test resistor and the matching capacitance value of the test capacitor are determined according to the actual capacitance value of the preset capacitance and the calculated capacitance value of the preset capacitance; the actual capacitance value of the preset capacitance is of the same order of magnitude as the capacitance value of the resonant capacitance of the chip to be tested.

3. The method for testing chip resonant capacitor according to claim 2, characterized in that: Determining, according to the difference between the second time and the first time, a calculated capacitance value of the preset capacitance when the test resistor and the test capacitor are at different preset values, comprises: T2-T1=(RO+R1)(CO+C1)-(RO+R1)CO; C1=(T2-T1) / (RO+R1); Among them, T2 is the second time, T1 is the first time, RO is the equivalent impedance of the test machine, R1 is the preset value of the test resistor, CO is the preset value of the test capacitor, and C1 is the calculated capacitance value of the preset capacitor.

4. The method for testing chip resonant capacitor according to claim 2, characterized in that: Determining a matching resistance value of the test resistor and a matching capacitance value of the test capacitor according to an actual capacitance value of the preset capacitor and a calculated capacitance value of the preset capacitor, comprising: Subtracting the actual capacitance value of the preset capacitor from the calculated capacitance values ​​of the plurality of preset capacitors respectively to determine the absolute values ​​of the plurality of differences; Selecting a calculated capacitance value of a preset capacitance corresponding to a minimum value among the absolute values ​​of the plurality of differences as a preset capacitance value of the preset capacitance; The preset value of the test resistor corresponding to the preset capacitance value is used as the matching resistance value of the test resistor, and the preset value of the test capacitor is used as the matching capacitance value of the test capacitor.

5. The method for testing chip resonant capacitor according to claim 4, characterized in that: The actual capacitance value of the preset capacitor is of the same order of magnitude as the calculated capacitance value of the preset capacitor.

6. The method for testing chip resonant capacitor according to claim 1, characterized in that: The capacitance value of the test capacitor is of the same order of magnitude as the capacitance value of the resonant capacitor of the chip to be tested.

7. The method for testing chip resonant capacitor according to claim 1, characterized in that: The test machine includes a comparator and a driver; the first input end of the comparator is connected to the output end of the RC circuit, the second input end of the comparator is used to input the preset voltage, the input end of the driver is connected to the output end of the comparator, and the output end of the driver is connected to the input end of the RC circuit; The obtaining of the first time or the second time includes: When the driver drives the RC circuit to charge, a pulse signal is synchronously output, and the pulse signal is counted; When the output signal of the comparator jumps, the first time or the second time is determined according to the number of the pulse signal.

8. The method for testing chip resonant capacitor according to claim 7, characterized in that: It also includes a driving chip, and the test machine is connected to the RC circuit through the driving chip; the driver drives the RC circuit to charge, including: The driving chip drives the RC circuit to charge according to the driving signal output by the driver.

9. The method for testing chip resonant capacitor according to claim 1, characterized in that: Before testing the resonant capacitance of the chip to be tested based on the matched RC circuit, the method further includes: Adjust the chip mode to test mode.

10. The chip resonant capacitor testing method according to claim 1, characterized in that: After testing the resonant capacitance of the chip to be tested, the method further includes: According to the obtained capacitance value of the chip to be tested, it is determined whether the capacitance value of the chip to be tested is within a preset value of the chip resonant capacitance.

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